I quite agree Phanto.
My point is people can choose to be offended, and they can choose not to be offended. Personally, I would not choose to be offended by someone I didn't know, or who didn't know me; their opinions could not be well informed and therefore not worth being taken seriously.
But that is a purely personal experience, and is in fact deliberately excluded from 18c-18d. The issue here is of a public broadcaster deliberately casting aspersions on the characters of people he couldn't possibly know; misinforming countless Australians and quite possibly causing not only mental but physical anguish by inciting others.
In short, he was generalising; putting a large number of people into the same boat and inferring they were all the same, with the same motives, feelings and ambitions, based on their ancestry.
This is the essence of racism.

Johnj : "Bolt has made allegations that particular people are not Aboriginal due to colour of their skin, making them feel that their family history - their parents and grandparents - are being erased."

You will find that Bolt did not allege that they were not Aboriginal due to colour of their skin. He would have been aware of former High Court Justice Deane's definition of Aboriginal that has become accepted as current law, viz.
" By "Australian Aboriginal" I mean, in accordance with what I understand to be the conventional meaning of that term, a person of Aboriginal descent, albeit mixed, who identifies himself as such and who is recognised by the Aboriginal community as an Aboriginal." (http://en.wikipedia.org/wiki/Aboriginal_Australians)

The following extracts from reports of the court case do not support your assertion:

" At issue was Bolt's assertion that the nine applicants had chosen to identify themselves as “Aboriginal” and consequently win grants, prizes and career advancement, despite their apparently fair skin and mixed heritage." (http://www.theaustralian.com.au/media/andrew-bolt-x-racial-vilification-court-case/story-e6frg996-1226148919092)

" Mr Bolt's series of blog posts that were found to have breached the law suggested that "fair-skinned" indigenous people took advantage of their heritage to make political or career gains. (http://www.smh.com.au/entertainment/tv-and-radio/abc-apology-fails-to-appease-andrew-bolt-20140318-34yug.html )

Isn't it funny how those who promote freedom of speech bleat being offended in the same breath ?
To have truly freedom of speech there can't be any offending then can there ?

Individual, you entirely miss the point. Those who defend free speech fully expect to be offended, and it is part of normal robust discussion to point out that something offensive - or false and misleading or unfair or whatever - has been said, and so allow one's interlocutor to reconsider what was said. The difference is that defenders of free speech do not seek to use the force of law to silence those who offend them. They just want to argue freely with fellow citizens on matters of public importance without the intrusion of the thought police.

David van Gend,
In an ideal world yes, but in Australia we have a whole army of feigned indignation soldiers & they're always on the lookout for earnest comments to be twisted as offensive.

Thanks, individual - I misunderstood your point. I thought you were having a go at situations such as where Andrew Bolt required an apology from ABC Q&A for their grossly offensive (indeed defamatory) smear - and a Prof of politics says there should be no recourse to ask for such an apology.

Explained by Andrew here: http://blogs.news.com.au/heraldsun/andrewbolt/index.php/heraldsun/comments/a_professor_rages_free_speech_means_never_having_to_say_youre_sorry_for_a_f/